Using sockets between android device and pc (same network)

Question

I have been struggling with this for a while now. What I'm simply trying to do, is to create a socket connection between my android app and my java program on PC.

I have both tried UDP and TCP sockets and different kinds of IP's and port numbers.

So, how can I achieve this?

Here is my (current code) with a (attempted) TCP connection:

Code snip from the server side (PC java program):

try {

    DatagramSocket socket = new DatagramSocket(4466);
    byte[] buffer = new byte[2048];

    DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
    socket.receive(packet);

} catch (SocketException e) {
  e.printStackTrace();
} catch (IOException e) {
  e.printStackTrace();
}

And the relevant snip from my android app (client):

try {

    InetAddress host = InetAddress.getByName("192.168.1.255");
    DatagramSocket socket = new DatagramSocket (null);
    byte[] buffer = new byte[2048];
    buffer = "hej hej".getBytes();

    DatagramPacket packet=new DatagramPacket (buffer, buffer.length, host, 4466);
    socket.send(packet);
    socket.close();

} catch(Exception e) {
    e.printStackTrace();
}

The IP address: 192.168.1.255 is supposed to be some kind of broadcast IP. But I have also tried different IP's like the IP for my PC (hard-coded in the android app), the 255.255.255.0, localhost and so on.

I would really appreciate it if anyone could help me out!

Answer 1

You need the public address of your computer (search for something like what's my IP) and make sure there's no firewall blocking the port. The 192.168.***.* address is not public (it's a LAN address), and the emulator (or an actual phone) won't able to see it.